Worldwide, regulatory bodies have begun to mandate the use of hands free systems for phone conversations in vehicles. A hands free system enables the driver to carry on a phone conversation without holding a phone to their ear. While some systems incorporate a headset, typically a hands free system comprises a microphone and speaker mounted in the vehicle and connected to a cellular phone mounted in a cradle. Existing systems typically require pressing keys on the phone or on a separate keypad embedded in the dashboard to dial a phone number. Newer systems use voice recognition, implemented as part of the hands free system or embedded phone system, to enable a true hands free operation. Some providers of applications attempt to use hands free systems (a.k.a. hands free kits) in tandem with the user's personal phone to deliver their service, removing the need for an in-vehicle embedded phone.
There exist disadvantages with current systems. A system based on a portable phone mounted in a cradle is inherently unreliable as the phone may become detached from its cradle at the time it is most needed (e.g., because of crash impact.) In addition, the driver may have forgotten their phone outside of the vehicle and only discover that when the phone is needed.
Bluetooth (BT) is a short-range wireless technology originally designed to replace patch cable between personal computers and related peripherals. This technology is making its way into mobile cellular phones to enable them to communicate over short range with other devices. BT applications may be connected to a personal phone in an in-vehicle hands free system. In one scenario, the driver gets into their vehicle and starts driving without pulling their phone out of their pocket. A BT transceiver that is part of the in-vehicle hands free system and the BT transceiver in the phone discover each other and establish a continuous wireless link. The hands free system now uses the driver's personal phone to connect with the cellular network.
The above solution suffers from limitations similar to the cradle solution and more severe. For example, wireless connections are inherently unreliable. On occasions the two systems do not establish a connection when the driver enters the car. Unlike when placing a phone into a cradle, there is no physical, tangible cue to the driver to indicate a likely connection failure. Even after the initial connection has been established, it may be dropped at any time; even in the middle of a conversation. In addition, the phone may be placed at a location in the vehicle with poor cellular reception (e.g. below glass window level) that does not have access to a vehicle mounted external antenna. Lastly, in dense traffic and given BT security issues, conversation privacy may be compromised as it may leak over the BT network to other vehicles in close proximity.
Therefore, there exists a need to provide a more reliable, less costly, hands free vehicle phone system.